1. Field of the Invention
This invention relates to an electrically activatable recording (EAR) element and process in which an inorganic interlayer between an electrically conductive support and an electrically activatable recording layer enhances imaging.
2. Description of the State of the Art
Electrically activatable recording elements and processes are known. They are described in, for example, U.S. Pat. No. 4,234,670. Such EAR elements are useful in forming images by electrically activated recording and dry processing techniques or processing techniques involving processing solutions or baths. Dye forming EAR elements and processes are also known, as described in, for example, Research Disclosure, October, 1979, Item No. 18627. It has been desirable to enhance image formation in the electrically activatable recording layer of such elements to enable formation of images having higher maximum densities without increasing the electrical current required for exposure and without adding components to the electrically activatable recording layer.
Certain organic interlayers are useful for aiding imaging in an EAR element, as described in, for example, U.S. Pat. No. 4,309,497. These organic interlayers comprise polymers that generally are expensive to prepare. In our attempt to replace such organic interlayers with less expensive interlayers we found that interlayers comprising many inorganic compounds do not enhance image formation in an EAR element. We found many inorganic compounds in such interlayers prevent image formation in an EAR element. This is illustrated in the following comparative examples. No answer to the problem of enhancing image formation in an electrically activatable recording layer by means of an inexpensive inorganic interlayer between an electrically conductive support and an electrically activatable recording layer in an EAR element was known in the prior art.